No one enjoys the nausea, vomiting, and fatigue that often come with early pregnancy.
But what if these uncomfortable symptoms serve a purpose beyond making expectant mothers miserable?
A new study suggests that morning sickness might actually be a positive sign—one that could indicate a lower risk of miscarriage.
For years, the idea that nausea means a healthy pregnancy has circulated as a common belief, but scientific evidence was lacking.
Now, researchers from the U.S. National Institutes of Health (NIH) have conducted a study that provides the strongest support yet for this theory.
“It’s a common thought that nausea indicates a healthy pregnancy, but there wasn’t a lot of high-quality evidence to support this belief,” says epidemiologist Stefanie N. Hinkle from NIH.
“Our study evaluates symptoms from the earliest weeks of pregnancy, immediately after conception, and confirms that there is a protective association between nausea and vomiting and a lower risk of pregnancy loss.”
So, does this mean morning sickness is a good thing?
Let’s explore what the research actually found and what it could mean for pregnant women.
A Closer Look at the Science
Past studies have attempted to link morning sickness with pregnancy outcomes, but none have examined symptoms in such detail during the crucial first eight weeks of pregnancy.
This is significant because up to 80% of women experience nausea during the early weeks.
To dig deeper, researchers analyzed data from the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial, which studied 797 women who had previously experienced one or two miscarriages.
The participants recorded their symptoms in daily diaries from the second to eighth week of pregnancy and then provided monthly updates until the 36th week.
The findings? Women who experienced nausea by the eighth week of pregnancy were 50% less likely to have a miscarriage.
Those who had both nausea and vomiting saw an even greater benefit—they were 75% less likely to experience pregnancy loss.
“These findings represent the most definitive data available to date,” the researchers note in their published study.
The results suggest that morning sickness may indeed play a protective role in pregnancy—but why?
Why Would Nausea Help Protect a Pregnancy?
This is where things get interesting. Scientists have several theories about why nausea might be linked to a lower miscarriage risk:
Evolutionary Advantage: Some researchers believe morning sickness evolved to help pregnant women avoid harmful substances.
Foods that trigger nausea (like raw meat, strong-smelling vegetables, or heavily spiced foods) may have posed risks to early pregnancies.
Hormonal Influence: The hormone human chorionic gonadotropin (hCG), which is produced by the placenta, has been linked to nausea levels.
Higher levels of hCG are often associated with stronger pregnancy symptoms—and possibly a lower risk of miscarriage.
Placental Health: Some researchers suggest that nausea could be a marker of placental viability.
In other words, pregnancies with stronger symptoms may have healthier placentas, leading to better overall outcomes.
But while these ideas are intriguing, they aren’t definitive. More research is needed to fully understand the relationship between morning sickness and pregnancy health.
What If You Don’t Have Morning Sickness?
At this point, you might be wondering: What if I’m pregnant but don’t have nausea? Should I be worried?
The short answer? No.
While this study found a correlation between morning sickness and lower miscarriage risk, it doesn’t mean that not having nausea is a bad sign.
“Not all pregnancies are the same, and every individual is different,” Hinkle told The Atlantic.
“So just because someone does not have symptoms does not mean that they will go on to have a loss.”
In fact, some women go through perfectly healthy pregnancies without experiencing nausea at all.
The absence of morning sickness doesn’t automatically indicate a problem—it may just mean your body reacts differently to pregnancy hormones.
What Does This Mean for Pregnant Women?
For women struggling with morning sickness, these findings might provide some reassurance.
While nausea is certainly unpleasant, it could be an indication that your pregnancy is progressing well.
At the same time, if you don’t have morning sickness, don’t panic. Every pregnancy is unique, and many other factors contribute to a healthy pregnancy.
This study opens the door for more research into how nausea, hormones, and pregnancy health are connected.
Scientists are still trying to determine the biological mechanisms behind this link—so stay tuned for future discoveries.
In the meantime, if you’re experiencing severe morning sickness, speak with your doctor.
There are treatments available to help manage symptoms so you can focus on enjoying your pregnancy journey.
